Malaria is an infectious disease caused by the protozoan parasites belonging to Plasmodium genus and is transmitted to mammalian hosts through the bite of infected mosquitoes. Four species of Plasmodium are pathogenic in humans: P. vivax, P. malariae, P. ovale, and P. falciparum. Several other species of Plasmodium infect animals. According to WHO reports, 214 million cases were reported in 2015, and the annual deaths attributable to malaria stand at 500 thousand to 1 million cases. Most of the cases were reported from Sub Saharan African region (88%), followed by South-East Asia. However, attacks of malaria are rather increasing due to the increasing resistance of mosquitoes against insecticides and the appearance of genetic variants of parasites resistant to anti-malarial drugs. Although, several drugs are known to be effective in clinical treatment of malaria, the emergence and spread of drug resistance poses a big problem in current malaria treatment and elimination programs. The parasitic protozoan Toxoplasma gondii is the etiologic agent for toxoplasmosis, a parasitic disease widespread among various warm-blooded animals. Afflicted people mostly carry the infection lifelong, with the potential to flare-up or recrudesce under immunocompromised conditions, and hence Toxoplasma infections tend to be chronic in nature, primarily due to their ability to persist in the host as latent cysts. Treatment options for Toxoplasma include antibiotics such as clindamycin or pyrimethamine/sulphadoxin combination, but the effectiveness of these against the cyst form of the parasite is still not clear and hence it is quite difficult to clear infection completely from infected individuals. It is estimated that ˜30% of the global population is infected by this pathogen, and is transmitted via the oral route by consumptions of contaminated food and water. Cats and other felines are primary hosts and can support sexual development of the parasite (akin to mosquitos in case of Plasmodium) and, the infectious forms of parasite (oocysts) are shed into the environment in cat feces. Clinical symptoms associated with Toxoplasma infection vary from severe (congenital encephalopathy in neonates) to mild (self limiting fever in healthy adults).
US 20120196882 A1 provides method of preventing or slowing the transmission of Plasmodium organisms between mammals by blocking oocyst formation and transmission of a Plasmodium parasite comprising administering to a mammal infected with malaria parasite or suspected of being infected with malaria parasite, artemisinin and one or two doses of ketotifen administered in doses of between 0.1 mg/kg and 0.5 mg/kg of ketotifen.
The Menshutkin reaction converts a tertiary amine to a quaternary ammonium salt by reaction with an alkyl halide. Source—Wikipedia

Article titled, “Synthesis of 4-Silapiperidine Building Blocks with N—H Groups Using the Staudinger Reaction” by Markus Fischer and Reinhold Tacke in Organometallics, 2013, 32 (23), pp 7181-7185 reports a novel acid-free method for the synthesis of 4-silapiperidine building blocks with N—H groups, using the Staudinger reaction as the key step.
Article titled, “4-Silapiperidine and 4-silapiperidinium derivatives: syntheses and structural characterization” by Tilman Heinrich, Christian Burschka, Martin Penka, Brigitte Wagner, Reinhold Tacke in Journal of Organometallic Chemistry, Volume 690, Issue 1, 3 Jan. 2005, Pages 33-47 reports a series of novel 4-silapiperidine and 4-silapiperidinium derivatives, with two silicon-bound aryl groups and various N-organyl groups, synthesized and structurally characterized. These investigations provide the basis for the development of novel silicon-based drugs containing a 4-silapiperidine or 4-silapiperidinium skeleton.
GB2396863 (A) discloses a compound of formula (I) R4 R1O∧ON/wherein R′ is hydrogen or alkyl; R2 and R3 are the same or different and are each alkyl; R4 is hydrogen, halogen, alkyl, NO2 or CF3; and R5 and R6 are the same or different and are each hydrogen, alkyl, halogen or alkoxy; or a pharmaceutically acceptable salt thereof. These compounds are calcium (Ca<2+>) channel blockers. These compounds may be useful in the treatment of cardiovascular diseases such as cardiac arryhythmia, glaucoma or hypertension. A preferred compound is sila-niguldipine.

WO 2014128724 A1 discloses silicon analogs of piperine of formula A with increased antibacterial efficacy and their preparation thereof. Further, a compound of general formula A,

wherein R1, R2 each are individually selected from H, hydroxy, alkoxy or R1 and R2 may form alicyclic or aromatic ring which may additionally contain one or two hetero atoms; R3, R4 each are individually selected from alkyl, aryl, alkoxy, halo or R3 and R4 may form alicyclic ring which may additionally contain an hetero atom; m, n=0, 1, 2.
The search for new antimalarial drugs is still in progress. However, the hope that new drugs would help eradicate the disease has not been realized. Accordingly, what is needed in the art are new treatments for effectively combating malaria, and particularly malarial forms that are resistant to current treatments, but without the side-effects and complications of drugs and treatments that are presently available. Also there is an urgent need for new and effective drugs for treating and preventing chronictoxoplasmosis.